Fluid control mechanism for a change speed gear transmission operated by fluid pressue



Oct. 31, 1939. K MAYBACH 2,177,904

FLUID CONTROL MECHANISM FOR A CHANGE SPEED GEAR TRANSMISSION OPERATED BY FLUID PRESSURE Filed July 1o, 19:55 4' Sheets-Sheet 1 I yJ/M v Oct. 31, 1939! K MAYBACH 2.177.904

FLUID CONTROL MECH ANISM FOR A CHANGE SPEED GEAR TRANSMISSION OPERATED BY FLUID PRESSURE Filed July 10, 1935 4 Sheets-Sheet 2 lnvudormM Oct. 31, 1939. K. MAYBACH 2.177.904

FLUID .CONTROL MECHANISM FOR A CHANGE SPEED GEAR TRANSMISSION OPERATED BY FLUID PRESSURE Filed July l0, 1935 4 Sheets-Sheet 3 Oct. 31, 1939. MAYBAH 2,177,904

v FLUID CONTROL MECHANISM FOR A CHANGE SPEED GEAR TRANSMISSION OPERATED BY FLUID PRESSURE Filed July 10, 1935 4 Sheets-Sheet 4 Patented Oct. 31,, 1939 I UNITED STATES FLUID CONTROL CHANGE SPEED MECHANISM FOR A GEAR TRANSMISSION OPERATED BY FLUID PRESSURE Karl Maybach, Friedrichshaten, Germany, as-

signor to Maybach-Motorenbau G. m. b. Friedrichshafen, Germany Application July 10,

' In Germany 9 Claims.

My invention relates to a fluid control mechanism for a change speed gear transmission operated by fluid pressure more particularly of power vehicles with distributer members controlling the admission of the pressure medium to the control cylinders of gear transmissions, the control occurring on cutting oil the gas or admitting gas, or in both cases. The device is to be worked chiefly by pressure medium, preferably pressure gas with over-pressure or under-pressure. My new fluid control mechanism is supposed to be added .to change speed gear transmissions operated by fluid pressure in a well-known manner,

as for example disclosed in the FrenchPatent No. 373,510 and in my U. S. Patent No. 1,883,743, or in my co-pending U. S. application Serial Number 30,760.

According to my invention it is essential that the admission of the pressure medium to the control pistons should not occur exclusively, for instance, in dependence on the movement of the gas lever, but that the admission of the pressure medium to the control pistons be also controlled in dependence on a movement occurring for se- 5 lecting the speed. Therefore, as soon as the setting of a pressure medium distributer to the position corresponding to the desired speed is effected, a further control member is simultaneously so set that the admission of the pressure D medium to the distributer members is released in accordance with the selected speed.

. This construction according to my invention has the advantage that the control passages and the spaces of the control cylinders are supplied 5 with pressure medium only if a speed has been previously selected. If no speed has been previously selected, then on the contrary no pressure medium will be supplied to the control passages and the spaces of the control cylinders, on cutting off the gas or on admitting the gas,

so that pressure medium losses during the numerous working periods are avoided on cutting oil the gas and admitting the gas.

The construction is according to my invention preferably such that the particular control member set onselecting the speed, is moved by the pressure of a pressure medium released-in dependence on the selecting movement. The return 15 movement of this control member is preferably effected by the pressure of the pressure medium employed for the control movements of the speeds. As soon as this is acting on the control .gj, pistons and consequently the control is more a or less complete, the control member dependent 1935, Serial no. 30,758 August 8,1934

upon the selection of the speed will also be returned to its initial position.

The control device with devlcecontrolling the pressure medium according to the invention is particularly suitable for such gears in which disengagement of the main clutch between the driving motor and the change gear is no longer required, for instance, gears with synchronizing devices or overrunning clutches, for instance, claw clutches which are alternately controlled and the claw end faces of which are so inclined that on moving the claw halves to be engaged towards each other, these clawhalves are ,repelled one by the other until the originally more rapid clutch half commences to be the slower one, and vice versa.

In the drawings are shown two constructional examples of the invention diagrammatically in section: I

Fig. 1 showing a control device with mechanical operation of the distributer members and the control member dependent upon the selection movement;

Fig. 2 a control 'device in which the distributer members and the control member dependent upon the selection movement are moved by pressure medium;

Fig. 3 is a diagrammatic view showing an arrangement of the distributor members and gear shifting motors used in the embodiment of Fig. 1 for a transmission such as shown in Fig. 4; Fig. 4 is a longitudinal elevation of a four speed transmission of the type employing claw clutches in obtaining the different gear selections;

Fig. 5 is a diagrammatic view illustrating the gear shifting motors and the connection thereof with the distributor valve for the embodiment of Fig. 2 as used with atransmission such as shown in Fig. 4;

Fig. 6 is a view taken on the line 6-6 01' Fig.

2 showing the details of the distributor valve; Fig. '7 shows the fixed plate coactingwith the distributor valve;

. Fig. 8 shows the construction of the selector cams in the embodiment of Fig. 2; and,

Fig. 9 is a diagrammatic view supplementary to Fig. 2 and showing the connection between conduit 18 and the operating motor of the main clutch.

From a pressure medium container I lead two conduits land 3 to a casing I. A .gas pedal lever 5 is connected with the lever i to which latter is pivoted the rod I of a piston disc 8. The piston disc 8 is loaded by a spring 9 and movably mounted in a spring casing I0. The spring casing I is pivotally connected with the elbow arm II of a lever I2. The lever arm I2 bears upon the stud I3 of a pin I4 of a valve I6 loaded by a spring I5. The movement of the pin I4 and therefore that of the valve I6 is limited by a stop 4' upon the casing 4. The valve I has a groove I! as well as an angular passage I0.

In the casing 4 is provided a further valve I9, I9 which possesses a groove as well as a face pin 2| against the shoulders 22 or 22 of which latter bears a locking pin 24 acted upon by a spring 23, which pin locks the valve I9, I9 either in its right or in its left hand position. In the casing 4 there is moreover provided a space 25 into which open two through passages 26 and 21. A passage 28 leads to a space 29 in the rear of a piston 30 against which bears a draw pusher 3|.

The space 32 is connected with the passage 34 and the latter with the air communication opening 33, and the passage 34 is moreover connected with a space 35 in front of one opening of which there lies a stop valve 31 loaded by the pressure of a spring 36, a passage 38 moreover branching oil from said space to a space 39. Into the space 39 moreover opens a passage 40. In space H slides a control valve 42, 42' which has a groove 43 and is loaded by a spring 44, such valve being one of a series of fluid pressure distributor valves which are selectively operated to effect operation of the gear shifting motors as hereafter explained in connection with Fig. 3. Within reach of the groove 43 of the control valve opens a conduit 45 leading to one of the gear shifting motors and within the reach of movement of the control valve piston 42 is provided in the casing 4 an air communication opening 46. A further opening 41 puts the spring space 4| in front of the control valve 42 into communication with the air. The space 48 in front of the left hand end face of the control valve I9 is moreover connected with the lower space 39 in casing 4 by a conduit 49 which has a throttle valve 50 close to space 39.

With the piston piece I9 of the valve I9 is moreover connected a'pusher 52 hearing against a cam disc 5|. The cam disc 5I is'moved by a hand lever 53 upon the shaft 54 on which is fixedly mounted at the lower end a second cam disc 55. The second cam disc 55 moves a pusher 50 provided upon the slide valve 42, 42'.

The number of control valves such as 42, 42' in Fig. 1 will be determined bythe number of gear shifting fluid motors to which the pressure medium is-to be 'distributed'and the number of such motors will vary in accordance with the number of different speed selections and/or the type of the transmission used. In Fig. 3 is shown an arrangement of twopairs of control valves, each pair distributing fluid to one of two gear shifting motors which provide the different gear selections in a four speed transmission suchas the illustrative one shown in Fig. 4, and hereafter to be described.

The control valve 42, 42' is as shown in Fig. 1, and serving through fluid conduit 45 to supply pressure to one side of piston I of the gear shifting motor I42. A similar control valve 424:, 42'a connecting with the space 39 through conduit 40a and port 40a supplies pressure to the opposite side of piston I through conduit 45a.

The second control valve 42b. 42'b in Fig. 3 supplies pressure through conduit 45b to one side of the piston I5I of the second gear shifting motor I62. Paired with such valve is a similar control valve 42c, 42'c which supplies pressure through conduit 45c to the other side of piston IN. The intake ports 40b and 400 of the two last mentioned valves are supplied with pressure from chamber 39 through connecting conduits 40b and 400'.

The selector cam disc 55 is rotated through its handle 53 to open and close the various control valves so that when fluid pressure is available in space 39 (Fig. 1) it may be distributed to the proper side of the respective gear shifting motors to produce the desired gear selection. The corresponding portions of the cam for the setting of all of the control valves for each gear selection is indicated in Fig. 2.

Before further explaining the operation of the mechanism just described, reference is made to can be disconnected from the clutch teeth provided at the left of gear 205, and at the same time clutch 202 can be engaged with clutch teeth provided at the left of gear 200.

Shift lever 208. of the double claw clutch 201 is mounted on shaft 209, and is operated by motor I62 through connection of piston IGI through rod I63 and arm I65 with shaft 209. On moving the piston I6I from its left to its right position the double claw clutch is disengaged from the clutch teeth provided at the right of gear 205, and engaged with the clutch teeth at the left of gear 2I0.

In the fourth speed position of the transmission, as represented by the position of the control valves in Fig. 3, the cam 55 is in position to hold open-control valve 42a, 4221 so that pressure is supplied to the left side of piston I. At such time valve 42, 42' closes port 40 and the right side of piston MI is opened to the atmosphere, through conduit 45 and port 45. Also under the same conditions, valve 42c, 42'c permits the flow of fluid from chamber 39 through conduit 40c and port 400 through conduit 45c to the right side of piston ISI of the second motor I82. The other side of piston IOI is vented through conduit 45?) and opening 401) due to the position of valve 42b, 42'b.

In shifting from fourth speed to third, for example, the control lever 53, and therewith cam disc 55 is rotated one subdivision. The positions of valve 42, 42', and valves 42a, 42'a remain unchanged. Piston I, and accordingly clutches 20I and 202 are therefore not moved. However, control valve 42b, 42'b, is opened through rotation of the cam from fourth to third speed position, and valve 420, 42'c, shifts to the left. Pressure is thus supplied to the left side of piston I52 through conduit 45b while the other side of the piston is opened to the atmosphere through 7( It will be vident that the arrangement of the 7:

control valves and operating motors is such that any gear selection may be obtained by rotation of the cam 55 from any previous set position.

The supply of pressure to space 33, from whence the same is distributed through the various control valves in the manner and for the purpose just explained is dependent upon the operation of theinventive structure as :shown in Fig. 1, and the latter will now be considered.

When the driver during drive turns the hand lever 53, the pusher 52 and therewith also the valve l9, l9 are moved to the left by the cam disc 5| and the slide valve is held by the locking pin 24 in its left hand end position. In this left hand position of the valve, a communication is established, via groove 28, between the pressure medium container l via conduits 2, 3 and passage 28 with the upper space in casing l,

' Be it now assumed that during this turning of the hand lever 53 (selecting motion), the driver still has his foot resting upon the gas lever 5, and that therefore the latter stands in any po sition corresponding to a certain opening of the carburetter.

The lever l2 would then be in its right hand end position so that the knob l3 of the pin ll would rest against stop 4' of the casing, and thevalve [6 connected with the pin ll'would also be in its right hand end position, in which the passage 28 is connected via angular channel l8 with the space 32 on the right of valve l8 and consequently via passage 34 with the air communication opening 33. By this means the space 29. behind the piston sleeve 38 is in communication with the air.

During the rotation of the shaft 5| effected by turning the hand lever 53, the cam disc 55 retates to the'same extent as the .cam disc 5| and the respective valves 42, 42a, 42b and 52c are selectively opened or closed in the manner heretofore explained. 1

If now the driver returns the gas lever 5 to the rest position, the valve, I8 is displaced under pressure of the spring l5 into the left hand end position shown in Fig. 1. During this movement of valve I5 the passages 21 and 28 are for a short moment in connection by means of the groove ll of the valve l5 and pressure air can pass from the conduit 3 via groove 28 in valve I 3, IS, the passage 25, the space 25, the passage 21, the groove II in valve 15 and the passage 28 to space 29. By this means, the piston sleeve 38 is displaced to the right, and thevalve 31 is opened by the draw-pusher 3| in opposition to the spring 36. a

Simultaneously, the lower opening of the passage 34 is closed by the draw-pusher 3|, and the spaces 35 and 33 are thereby separated from air communication opening 33. Now, pressure air can pass from the conduit 2 through the opened valve 31, the passage 38, the space 38, one of the ports 48, 48a, 48b, 40c and the groove in the particular control valves which are open, through the particular conduits 45, a, 45b, 450, which are openedthereby to the proper sides of the pistons of the respective gear shifting motors for the desired speed. This speed will therefore be put in after the return of the gas lever to rest position.

The pressure used for the control passes from the space 39 via throttling point 58 and conduit 43 to the space 48 and presses in the latter the valve l3, l3 standing in its left hand end position back-into its right hand end position, slid-- tion the slide again closes admission of pressure cam disc 5|, by known means being caused to turn over at least one breadth of a cam so that there is always a gap between two cams standing opposite to pusher 52' allowing for its movement to the light.

On gas being admitted by depression of the pedal lever 5 by the driver, the valve I6 is shifted to the right so far that the knob l3 of the pin ll bears upon stop 4' and the valve I8 is again displaced into its right hand end position in which it connects as already above described, the space 29 with the outer air. The valve 31 closes under the action of spring 38, the draw-pusher 3|, receding before the valve 31, renders free the lower opening of the passage 34, and the piston 38 returns again into the left hand end position shown in Fig. 1. By the release of the lower opening of passage 34', the control cylinder acted upon by pressure air, is connected via the corresponding one -of the conduits 45, 45a, 45b, 45c with the outer air via the following path: the correspond.- ing one of the ports 48, 48a, 48b, No, space .39, passage 38, space 35, passage 34, air communication opening 33. During further admission of gas by the driver, the spring 9 is suitably tensioned by the piston disc 8 moving with the gas lever 5, 6. During the movement of the valve l6 from its left hand into its right hand end position, the passages 21 and 28 are connected together by the groove 11 of the valve IE, but the pressure air admission to the space 23 is not effected thereby, as the valve l9, 19 has not admitted further pressure air to the space 25.

If the selection of the speed occurs during rest position of the gas pedal lever,the operations during selection and setting will take place in exactly the same manner as above described. During admission of the-gas, pressure air is admitted to the space 29 and the valve 31 is thereby opened, owing to the passage connections 21., 28 being slid over by the groove ll of the valve 18.

The passage [8 may be entirely omitted and communication of the space 29 with air may be effected by existing leakages without otherwise changing the construction. as shown in Fig. 1.

On cutting off the gas supply, if no speed has bonduits and passages communicating with the' control cylinders, nor the control cylinders themselves, are supplied with pressure air.

Therefore, during normal cutting off of the gas, no pressure air losses of any kind will occur, this being for the same reason also the case during the admission of gas and in the rest position of the gas lever 5.

In the constructional example according to Fig. 2, 8| is-the casing of-the speed selector, which is closed at its upper and lower ends by the covera 82 and 83. Upon the shaft 54 of. the speed selector which is set by a small hand wheel 68, which may be located above the steering wheel 85 or at any other point accessible to the driver,

' is mounted a cam disc 81 as shown in Figure 8 which moves a slide pin 88. 89 is a stop valve,

" loadedby a spring 18, for the pressure air admitted'from the branch conduit 88 connected to the-,conduit 2. "is a conduit connected behind the valve 69, 12 is an air communication opening. 13 is an angular passage which passes pressure air admitted from the conduit 88 to the slide pin 15 connected wtih the piston 14, which is under the action of the spring 16. 11 is a connection conduit leading to the casing 9| containing the control parts. The conduit 18 leads to the operating device of the clutch as shown in Figure 9 hereafter to be described.- The slide pin 15 is moved by the cam disc 19 as shown in Figure 8. With the shaft 64 of the speed selector is connected by a pin 88 the distributer disc 8| which turns over a plate 63 to which latter are connected the conduits 82 and 83 leading to the control cylinders of the gear. In the distributor disc 8| is a series of ports 86, 86a, 86b and 86c adapted to be selectively brought into registry with conduit 82 upon rotation of disc 8|. A corresponding set of ports 86, 86a, 86b and 86c are also disposed in the disc to register with conduit 83. 89 is the space above the distributor disc 8| to which air is supplied from conduit 81. Located in plate 63 is an air vent 98 registering with certain passages 98 and 98b in disc 8| as will be clear from Figures 2 and 6. In Fig. 2 the disc 8| is set for second speed position, and in Fig. 6 and the corresponding view, Fig. 5, it is set to fourth speed position.

' The arrangement of ports and grooves in disc 8| as just referred to, is particularly intended for use with a 4-speed transmission such as shown in Figure 4, and wherewith two gear shifting motors are employed. Referring particularly to Figure for the first speed ports 86c and 86c are both in registry with the respective conduits 82 and 83 so that pressure is, simultaneously supplied to such conduits from space 89 which connects with supply pipe 81. In the second speed position which is shown in Fig. 2 port 86b registers with conduit 82 to supply pressure thereto, but port '11, which does not extend completely through disc 8|, communicates through passage 98'b with opening 98 so that conduit 83 is vented to the atmosphere through the latter. In the third speed position port 86a registers with conduit 82 and vents such conduit to the atmosphere. It will be observed that ports 86a and 86 neither extend completely through the disc, but are interconnected by passage 862:. Port 86 communicates through passage 98 with opening 98 in plate 63. Hence, when port 86a registers with conduit 82 pressure will be exhausted from the conduit through port 8611, passage 861:, passage 98' and opening 98. correspondingly, in the third speed position, pressure will be supplied from space 89 to conduit 83 through port 86a. In the fourth speed position, as represented in Figures 5 and 6, the pressure in both conduits 82 and 83 will be vented to the atmosphere through ports 86 and 86 which are interconnected with each other and put in communication with opening 98 through passage 98.

To the lower portion of the casing 9| is connected the conduit 2, to the upper part the conduit 92 branched off the conduit 2. 93 and 94 are pressure air valves which are loaded by the springs 95 and 96. 91 is a slide valve corresponding to the control valve I9 of Fig. 1, which is held in a similar manner as shown in Fig. 1, in its two end positions by suitable locking means, such for example as a spring-pressed ball or finger 91a ,coacting with recesses 91b and 910 in valve 91,

and which possesses a cross passage 98 as well as a groove 99. Under the slide valve 91 opens theconduit 1| coming from the speed selector.

To the space under the valve 93 is connected a passage I88 which opens at the slide valve 91. 8| and I82 are passages in the casing 9|. I 83, I84 and I85 are bores which establish communication with the outer air. The valve 94 is moved by the pin I86 which can be lifted by the lever 'I 81 by means of the cam I88 by the gas lever I89. The valve 93 is moved by the pin II8 which is in connection with the piston III. Via passage I33, the space under the piston III is in communication with the bore I83 leading to the exterior, to which is connected the passage I28. Into the space I38 above the piston III opens a communication passage I21 which leads to the slide valve H2. The latter possesses at its upper end a disc-shaped projection I I3 and moreover a groove II4. From below, the slide valve IE2 is loaded by the spring I34. The two slide valves 91 and H2 are in connection via passage H5. The space provided above disc II3 of the slide valve H2, is in communication via passage I I G with the guide bore of the slide valve I86.

From the space above the piston I II leads a passage II1 to a further slide valve II8 which latter is loaded at its upper end by a spring H9 and has a groove I29 and has at its lower end an extension pin I28. I3I is a connection passage to passage I32 to which latter is connected conduit 81. Into the space under the slide valve II8 leads a conduit |2I which is connected to a conduit I22 which latter-is in connection with the control cylinders I42 and I62 for operating the change gear I23 as shown diagrammatically in Figure 2 and in detail in Figure 5. Conduit I22 also leads to the cylinder I24 of an auxiliary device for moving the throttle valve I25 for purposes hereafter mentioned. Into the linkage which starts from the gas lever, for moving the throttle valve, is built a spring device I26.

As heretofore mentioned, the particular construction of control disc 8| and the arrangement of conduits 82 and 83 is intended to function with a four speed transmission, such as shown in Figure 4, already discussed in connection with the embodiment of the invention in Figure 1. Two control cylinders are again used, and the latter may be arranged as shown in Figure 4. Therein, MI and I 6| are pistons of two compressed air motors I42 and I62, the piston rods I43 and I63 of which are moved by means of links I44 and I 64, and levers I45 and I65. Such levers are respectively connected to shafts 284 and 289 of the transmission of Figure 4 to actuate claw clutches MI, 282 and 281. In a side chamber of motor I42 is a slide valve I46 having a groove I58 formed between opposing portions I41 and I48, and a second groove |5| between portion I48 and I49. Spring I51 normally holds valve I46 in its left end position. The second motor I62 has a similarly arranged slide valve I66 with portions I61, I68 and IE9, grooves I18 and HI, and spring I 11. In the respective motors I 42 and I62, passages I52 and I53, and I12 and I13, connect the spaces of the slide valves with the cylinder spaces lying in front and in the rear of the pistons I4I and NH. To the casing portions of the cylinders which contain the slide valves are connected on the one hand conduits 82 and 83, which come from the speed selector mechanism, and on the other hand the conduit branches I54 and I55, and I14 and I 15, which latter branch from a common conduit I88. Between conduit I68, coming from conduit 81 and the conduit I88 is interposed a slide valve I82 loaded by a spring I8I, which has a groove I83 and an angular chanilel I84, the latter communicating with groove I83 through a small cross passage I85. I56 and I16 are air communication openings in the casings of the motors.

when air pressure is admitted to the casing of slide valve I46 in motor I42 from conduit 82, such valve is displaced into its right end position in opposition to the force of spring I51. If, at the same time conduit 83 is vented to the atmosphere through opening 88 in plate 63, no pressure is admitted to slide valve I66 of motor I62. Valve I66 therefore remains in its right end position under the force of spring. I11.

By means of conduit I68, which connects with conduit 81, air pressure passes to the slide valve I82 through an angular passage I84 into the space under such valve, which is then displaced in opposition to spring I8I into its'upper position. Passage I84 is so dimensioned that the movement of slide I82 upwardly is retarded relative to the control movement of slide .valve I46. With slide valve I82 in its upper position air pressure from conduit I68 passes through the annular space I83 to conduit I88. The pressure simultaneously passes as before under valve I82 through passage I85 so that slide valve I82 is held in its upper position. From conduit I88 the pressure passes into branches I54 and I14, assisting inholding slide valve I46 in its right end position while at slide valve I65 further passage is closed by the end portion I68.. Also, through passages I55 and I15 air pressure passes from conduit I88 through groove I5I of slide valve I46 and passage I53 to the space on the right of piston HI, and also, in motor I62, pressure passes through groove I18 of slide valve I66 and passage I12 into the space on the right of piston I6I'. Piston MI is displaced by the action of the air pressure into its left end position and the previous engagement of the clutch is changed. Piston I6 I is held by air pressure in its assumed left end position.

The shifting of piston I4I from its right to its left position, and/or the shifting of piston I6I' from its left to its right position will be readily understood. It will be noted in this connection that the air for actuating the pistons is supplied from conduit I88 to either side of the pistons selectively through slide valves I46 and I66. Such 'slide valves are controlled through passages 82 and 83 by the admittance of pressure to or the venting of conduits 82 and 83 through the selector mechanism of the invention.

The piston I24, previously referred to, is an auxiliary mechanism acting on gas throttle valve I25, and is intended to be employed in transmissions as shown in Figure 4 having claw clutches so that during the repelling, periods of the claws one clutch half may be retarded or accelerated to bring the same as rapidly as possible to the speed of the other clutch half, and thus hasten clutching engagement between the two. As soon as the repelling period terminates, and the required gear selection is obtained by clutch engagement, the control of the pressure medium admitted to the motors may be reversed.

The pressure in line I22 acting on piston I24 (Fig. 2) is controlled in'the present instance through apparatus incorporated in gear shifting motor I62 as shown in Figure 5. In piston rod 2 I63 is a bore 2 and connecting longitudinal groove 2 I2, and a second longitudinal groove -2I3.

When pressureis supplied from line I88 to the right hand side of piston I6I' and such piston has been moved sufficiently far to the left to bring one clutch half in the transmission into preliminary rattling engagement with a preceding clutch half, line I22 is connected with the chamber on the right of piston I6I through bore 2I I and groove 2I2. Pressure is accordingly supplied from the piston chamber to line I22 to act on piston I24 of the throttle valve motor, and to the adjoining line I2I to effect raising of slide -valve H8, all of which will be clear from a joint half. This enables the clutch halves to be brought into final clutching engagement for the desired gear selection in the transmission, piston I6I then moving into its left end position. As soon as piston I6I has reached the latter position, lines I2I and I22 are vented to the atmosphere through groove 2 I 3 in piston rod I83. Reduction in pressure in lines I2! and I22 causes slide valve H8 and piston I24 to return to their lower end positions through the action of their springs. Throttle valve I25 is again closed and pressure is cut off from line 11. The shift operation is now completed.

Conduit 18 (Fig. 2) ,as previously stated, is intended to be connected with the main clutch of the vehicle. An arrangement for this purpose is shown in Figure 9 whereby the pressure is utilized to operate the control motor of the clutch. Therein conduit 18 leads to one end of a housing 225 wherein is a slide valve 221 provided with a transverse bore 228. Conduit 238 connects nousing 225 with the pressure supply of the main reservoir. A further conduit 23I under control of valve 221- supplies pressure to piston 238 of the servomotor 232 of the clutch. Valve 226 is urged upwardly by spring 226 and when in raised position provides communication through its bore 228 between conduits 238 and 23I. Pressure medium is thus caused to move piston 238to the right and effect disengagement or the clutch.

When pin 15-is in its right position and pressure is supplied through conduit 18, slide valve 221 is forced downwardly to close conduit 238. At such time pressure previously acting on piston 238 is vented through groove 228 in the valve 221 and 'port 235 which registers with such groove. The

act on slide valve 221. 'Slide 221 is therebymoved into its lower end position, in which it connects the passage 23I from servomotor 232 with the de-aerating bore 235 in housing 225 by means of the groove 228. The clutch 233 is connected in through the action of the or coupling spring.

usual clutch During the shifting operation, that is as longas passage I22 (Fig. 2) is filled with pressure medium and slide I I8 assumes its upper position under pressure supplied through line I2I, piston 14 and therewith pin 15 is moved into its left end position by the pressure medium from passage III fed through passage I7, in which end position pin I5 engages in a groove of disc I9 and prevents it from rotation. At the same time, through the part 236 of pin 15 at the right of recess 234, connection between passage I3 and I8 is interrupted. The excess pressure above slide 221 in housing 225 escapes through leak points or over a groove 23! provided in the pin part 236 through a de-aerating bore 238 provided in housing 6I. Slide 221 is thereby forced by its spring 226 into its upper end position in which, through its transverse bore 28, it connects the pressure medium feed passage 230 with the passage 23I. Piston 239 is moved to the right and the clutch 233 disconnected. After shifting is completed passage I22 is again de-aerated, slide H8 thereby carried into its lower end position upon release of pressure in line I 2I and the pressure medium supply TI to piston I4 cut off, said piston I4 then returning through the action of its spring 16 into its right end position limited by the stop 240. The connection between the passage I3 and the passage 18 is again established, and slide 221 forced into its lower end position, passage 23I therewith connected through the groove 229 with the de-aerating bore 235 and the clutch again connected in.

The mode of operation of the device according to Fig. 2 is the following:

In the drawings the various parts are shown in the position assumed in the rest position of the gaslever. As the pin I06 is in its lower position, valve 94 is closed. The space above the disc H3 is therefore connected via passage II 6 and the air communication bore I05 with the outer air, and the slide valve H2 is under the action of the spring I34 in its upper end position.

On turning the hand wheel 66, the valve 69 is opened against the force of the spring 10 by means of the cam disc 6! by the pin 68. Pressure air consequently passes through the conduit II under the slide valve 91 which latter is thereby displaced into its upper position and is held in this position by engagement of spring-pressed ball 9111 with recess 91b in slide valve.

By the movement of the slide valve 91 into its upper end position, pressure air from the conduit 2 passes into the passage I I5 through passage I and the bore 98 of the slide valve 91.

By the setting of the distributer disc by the hand wheel 66, those of the conduits 8285 which are required for setting the selected transmission, were connected by the corresponding control passage 86 with the space 89, and consequently the admission for the pressure air to the corresponding control members of the gear was established.

As soon as the driver now admits gas the bore I is closed by the pin I06 and thereby the connection with the outer air is interrupted. Simultaneously valve 94 is lifted so that pressure air passes from the conduit 92 through the passage II6 above the disc II3 of the slide valve H2 and depresses the latter into its lower position. So long as gas is admitted, the slide valve H2 is held in its lower position by the pressure medium passed above the slide valve. During the sliding over of the communication passage I21 during its downward movement, the pressure air contained in the passage II 5 passes above the piston III, presses same downwards, closes there by by means of the pin II 0 the small passage I29 leading to the .air communication bore I03, and lifts the valve 93. Pressure air consequently passes through the conduit 81 into the space 89 and from the latter through the passage 86 into the conduits leading to the control cylinders of the change gear. The selected transmissionis therefore now set. Simultaneously pressure air passes via the inclined passage I02 and the passage IOI above the slide valve 91, which latter is thereby displaced back into its lower position, in which via longitudinal groove 99 the passage- II5 is via passages IOI and I02 again filled with pressure air.

This described arrangement is particularly used with gears with overrunning claw clutches in which the end faces of the claw teeth are so inclined that engagement occurs only upon overrunning of the slower running clutch half by the more rapidly running clutch half (disclosed in my U. S. Patents Reissue 17,707, Nos. 1,949,167 and 1,949,168) and in which auxiliary devices are provided by which during the repelling condition one clutch half is retarded or accelerated, as disclosed for example in my U. S. Patents Nos. 1,891,678 and 1,883,743. With such gears, the conduit I2I is connected to a conduit conveying the controlled pressure medium, ofthe corresponding auxiliary device; in the illustrated example this is the conduit I22 which leads to the cylinder I24, the piston of which moves the throttle valve I25, the spring device I26 interposed in the normal gas linkage permitting of a movement of the throttle valve, without the normal linkage of the gas pedal I09 being moved at the same time. By the pressure in the conduit I2I coming from the clutch motor cylinder I62 through conduit I22 under control of piston I6I as explained in connection with Fig. 5, the slide valve H8 is displaced upwardly, and by the groove I29 of this slide valve the passage I3I is connected with the passage 1, so that pressure air admitted by the valve 93 can also pass above the piston III. The valve 93 is therefore held open by the pressure released thereby until the pressure existing in the passage I2I disappears, and the slide valve I I8 moves back into its lower position, that is so long as the repelling condition of the engaged claw clutch of the gear lasts. As previously explained, the pressure in conduit I22, and hence in passage I2I, after operation of gear shifting motor I62 (Fig. 5) to bring the clutch teeth (Fig. 4) into repelling condition, is changed through groove 2 I3, or through groove 2I2 and bore 2, in the piston rod I63 of motor I62.

So long as the slide valve H8 is in its upper position, pressure air also passes through the conduit 11, to the space on the right of the small piston I4 so that the latter is slid against the action of the spring I6 into the recess of the disc I9 lying opposite to the slide pin connected with the piston. This prevents during the proper controlling operation, a new selecting movement being carried out by which obstructions might occur.

A particular advantage as regards safety, results, in the described arrangement, from the fact that at any setting of the control all the control slides are set by the pressure means, so far as the same are not already held in the required position by spring force, and that the pressure medium is passed to all the control pistons, that is, unless the latter are already, due to a previous setting, in the correct position for the speed to be set, in which case they are not displaced by the action of the pressure medium, but only held in their previous positions.

While in the several embodiments herein illustrated and described pressure above atmospheric is employed, the basic features of the invention are not to be taken as limited in this respect, since suction and pressure are commonly employed interchangeably in'the art in which the present control mechanism falls.

I do not want to be limited to the details described or represented in the drawings as many variations will occur to those skilled in the art.

What I claim is:

1. A control device for pressure-operated gear shifting mechanism in motor'vehicles comprising a series of distributor valves controlling the distribution of pressure to the gear shifting mechanism for various selections, means for se-- lectively setting said distributor valves for various gear selections, a source of fluid pressure, a

, valve controlling the supply of pressure from the source to the distributor valves, and pressure controlled actuating means for opening .and closing said supply control valveincluding a second valve controlling the operating pressure for actuating the supply valve operated by the distributor valve setting means, an operating lever controlling the supply of gas to the motor, a third valve operated by said lever controlling the operating pressure for actuating the supply valve, said second and third valves being in series so that the actuating pressure for operating the supply valve of the distributor valve series is dependent on both of said valves.

2. A fluid control mechanism as claimed in claim 1 further including fluid pressure means for closing said second valve, said means being operative in dependency on said third valve.

-3. A fluid control mechanism as claimed in claim 1 wherein the supply valve controlling the admission of 'fluid pressure to said distributor valves is controlled by said third valve, and fluid pressure means for closing said second valve, said means being operative in dependency on said third valve.

4. A fluid control mechanism as claimed in claim 1 further including the feature that said third valve is closed in both its end positions and opens only momentarily while moving from one position to the other and vice versa.

-5. A control device for pressure operated gear Y shifting mechanism in motor vehicles comprising a series of distributor valves controlling the distribution of pressure to the gear shifting mechanism for various gear selections, means for selectively setting said distributor valves for various gear selections, a source of fluid pressure, a valve controlling the supply of pressure from the source to the distributor valves, an operating lever con-. trolling the supply of gas to the motor, pressure controlled actuating means for the supply valve, a valve controlled by the gas lever controlling the flow of pressure to saidactuating means, said valve controlled by the gas lever having two closed end positions and being adapted to open only momentarily when being moved from one p0 sitlon to the other and vice versa, and a further valve controlling the flow of pressure to said actuating means actuatable by the distributor valve setting means.

6. A control device for pressure operated gear shifting mechanism in motor vehicles comprising a series of distributor valves controlling the distribution of pressure to the gear shifting mechanism for various gear selections, means for selectively setting said distributor valves for various gear-selections, a source of fluid pressure, a valve controlling the supply of pressure from the source to the distributor valves, an operating lever controlling the supply of gas to the motor, pressure controlled actuating means for the supply valve, a valve controlled by the gas lever controlling the flow of pressure to said actuating means, said valve controlled by the gas lever having two closed end positions and being adapted to open only momentarily when being moved from one position to the other and vice versa, and a further valve controlling the flow of pressure to said actuating means actuatable by the distributor valve setting means in one direction, and fluid pressure means operating in dependency on the valve actuated by the gas lever for moving said further valve in the other direction.

'7 In a control device for pressure-operated gear shifting mechanism in a motor vehicle, a series of distributor valves controlling the distribution of pressure to the gear shifting mechanism for various gear selections, means for selectively setting said distributor valves for various gear selections, a source of pressure, and control valve means operating in dependency on movement of the distributor valve setting means controlling the flow of pressure from said source to the distributor valves.

8'. In a control device for pressure-operated gear shifting mechanism in a motor vehicle, a,

series of distributor valves controlling the distribution of pressure to the gear shifting mechanism for various gear selections, means for selectively setting said distributor valves for various gear selections, a lever controlling the supply or gas to the vehicle motor, a source of pressure,

and control valve means operating in dependency on the distributor valve setting means and in dependency on the gas control lever controlling the flow of pressure from said source to the distributor valves.

9. In a control device for pressure-operated gear shifting mechanism in a motor vehicle, a series of distributor valves controlling the disanism for various gear selections, means for selectively setting said distributor valves for various gear selections, alever controlling the supply of gas to the vehicle motor, a source of pressure, control valve means controlling the flow of pressure from said source to the distributor valves, and actuating means controlled by the gas lever and by the distributor valve setting means for opening and closing said control valve means.

KARL MAYBACH.

, tribution of pressure to the gear shifting mech- 

